package com.ls.lock;

import java.util.*;
import java.util.concurrent.CopyOnWriteArrayList;

//集合线程不安全
public class LThreadDemo3 {
    public static void main(String[] args) {
//        List<String> list = new ArrayList();//不安全
//        List<String> list = new Vector<>();//安全
//        List<String> list = Collections.synchronizedList(new ArrayList<>());
        List<String> list = new CopyOnWriteArrayList<>();

        for (int i = 0; i < 30; i++) {
            new Thread(() -> {
                list.add(UUID.randomUUID().toString().substring(0, 8));
                System.out.println(list);
            }, String.valueOf(i)).start();
        }

    }
}
